<h2 id="heading-url">URL</h2>
<a target="_blank" href="https://leetcode.com/problems/n-th-tribonacci-number/description/?envType=daily-question&amp;envId=2024-04-24">N-th Tribonacci Number - LeetCode</a>
<h2 id="heading-code">Code</h2>
<a target="_blank" href="https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/challenge/202404/nth_tribonacci_number/main.fsx">https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/challenge/202404/nth_tribonacci_number/main.fsx</a>
<pre><code class="lang-fsharp">let tribonacci (n: int) : int =
 let rec tribonacci' i n prev1 prev2 prev3 =
 if i &gt; n then
 prev1
 else
 tribonacci' (i + 1) n (prev1 + prev2 + prev3) prev1 prev2

 match n with
 | 0 -&gt; 0
 | 1
 | 2 -&gt; 1
 | _ -&gt; tribonacci' 3 n 1 1 0
</code></pre>

## URL

[N-th Tribonacci Number - LeetCode](https://leetcode.com/problems/n-th-tribonacci-number/description/?envType=daily-question&envId=2024-04-24)

## Code

[https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/challenge/202404/nth\_tribonacci\_number/main.fsx](https://github.com/syohex/dotnet-study/tree/master/fsharp/leetcode/challenge/202404/nth_tribonacci_number/main.fsx)

```fsharp
let tribonacci (n: int) : int =
    let rec tribonacci' i n prev1 prev2 prev3 =
        if i > n then
            prev1
        else
            tribonacci' (i + 1) n (prev1 + prev2 + prev3) prev1 prev2

    match n with
    | 0 -> 0
    | 1
    | 2 -> 1
    | _ -> tribonacci' 3 n 1 1 0
```

LeetCode 1137. N-th Tribonacci Number in F#

URL

Code